I need to know how to set up these claculations for a lab, Can someone give me t

Question

I need to know how to set up these claculations for a lab, Can someone give me the step by step equations on what I should do? We will start with a liquid sample of pure acid with a given g/L.

The calcualtions I need help with are.

Calculation for Mass of acid titrated for titration #1?

Calculations for moles of NaOH added for titration #1?

Calculation for EW for titration #1?

Calculation for average Equivalent Weight?

Avg Value of Equivalent Weight?

All the information that we have is :

"Your first objective is to determine the volume of acid that requires between approximately 25 to 40 mL of 0.1XX M NaOH to titrate. This range of titrant volumes will give you the best combination of accuracy and experimental ease.

Start by titrating 25.00 mL of the unknown acid.

1. Carefully pipet 25.00 mL of the unknown acid using a volumetric pipet. Place it in a clean 250 mL Erlenmeyer flask.

2. Add 3 drops of indicator.

3. Titrate with NaOH until the endpoint is reached.

The Data table I need to fill out is

Mixture #1 Volume of acid titrated Mass of acid titrated Initial buret volume Final buret volume titrant volume delivered moles of NaOH Added Equivalents Weight of Acid

Explanation / Answer

This is a titration experiment. What Ican do for you is I can help you with an example of a specific type of acid-base titration and you just have to follow up.

These are you steps to follows up in the experiment:

1. Carefully pipet 25.00 mL of the unknown acid using a volumetric pipet. Place it in a clean 250 mL Erlenmeyer flask.

2. Add 3 drops of indicator.

3. Titrate with NaOH until the endpoint is reached.

After the experiment, you will be having the following data with you:

volume of acid titrated= 25 ml (say)

Initial buret volume of NaOH= 50 ml (say)

Final buret volume of NaOH= 37.0 ml (say) Always check the lower meniscus.

Titrant volume delivered = 50-37 = 13 ml = 0.013 Ltr

Now, calculation part:

The equation involved is (assuming the unknown acid is monoprotic):

HA + NaOH <==> NaA + H2O

At the neutralization point, the moles of acid (HA, for monoprotic acid only)=moles of base NaOH

Now, moles of base NaOH titrated= molarity of NaOH* Volume titrated (in Ltr) = 0.1 M* 0.013 Ltr = 0.0013

So, at neutralization point, moles of monoprotic acid = 0.0013

Volume of acid taken for titration= 25 ml = 0.025 Ltr

So, molarity of unknown monoprotic acid solution= moles/volume (in Ltr) = 0.0013/0.025 = 0.052 M

Calculation for Mass of acid titrated for titration= moles of acid used for titration* Molar mass of acid

Calculations for moles of NaOH added for titration= moles of NaOH consumed* Molar mass of NaOH

The equivalent weight of a solution is the molecular weight of the solute, or dissolved substance, in grams divided by the valence of the solute.

For NaOH, valence =1, for a monoprotic acid, valaence=1, diprotic=2 ...

Calculation for EW for titration:

So, EW of acid= Mol. weight of acid/1

EW of base NaOH= Mol. weight of NaOH/1

Calculation for average Equivalent Weight= (EW1+EW2+ ...EWn)/n = x (say)

Avg Value of Equivalent Weight= x

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